Description
Thymic stromal lymphopoietin (TSLP) is an IL-7-like epithelial cell-derived cytokine that supports differentiation and long-term growth of B cells (1). It is expressed in the heart, liver, testis and prostate. TSLP overlaps biological activities with IL-7 and binds with the heterodimeric receptor complex consisting of the IL-7R alpha chain (IL-7Rα) and the TSLP-specific chain (TSLPR). Like IL-7, TSLP induces phosphorylation of STAT3 and STAT5 but uses kinases other than the JAKs for activation. It activates DCs primed naïve T cells to produce the proallergic cytokines (IL-4, IL-5, IL-13, TNFα) while down-regulating IL-10 and IFN-γ suggesting a role in initiating allergic inflammation (2-3). TSLP prohibits apoptosis and stimulates growth of the human acute myeloid leukemia (AML)-derived cell line MUTZ3. It induces the release of T cell-attracting chemokines TARC and MDC from monocytes and activates CD11c(+) dendritic cells (4)